Dietrich Bonhoeffer was accused of being involved in the 20 July plot to assassinate Hitler, depicted in the film Valkyrie (2008), after Hans von Dohnanyi was accused of being the "spiritual leader" of the attempt. There is no evidence that either man was involved in that particular event and was just pretense to eliminate both.
Originally tentatively titled "God's Spy."
Niemoeller actor August Diehl previously portrayed an SS Gestapo officer in Inglourious Basterds (2009) and a German citizen who resisted enlisting in the German army in A Hidden Life (2019).
The attempted assassination attempt depicted in the film was real, though in reality Hitler simply rushed his tour of the captured munitions rather than mysteriously skipping it. While there is no proof Dietrich Bonhoeffer was involved with this or any other plot, he most likely knew of several attempts.